.checkers-board {
  width: 600px;
  height: 600px;
  border: 2px solid #333;
  margin: 20px auto;
}

.board-row {
  display: flex;
  height: 10%;
}

.board-cell {
  width: 10%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.white-cell {
  background-color: #f0d9b5;
}

.black-cell {
  background-color: #b58863;
}

.checker {
  width: 80%;
  height: 80%;
  border-radius: 50%;
  cursor: pointer;
}

.white-checker {
  background-color: #fff;
  border: 2px solid #ddd;
}

.black-checker {
  background-color: #333;
  border: 2px solid #222;
}

.checker:hover {
  box-shadow: 0 0 10px rgba(0,0,0,0.5);
}

.checker.selected {
  box-shadow: 0 0 15px #4CAF50;
  transform: scale(1.1);
}

.checker.king::after {
  content: '王';
  position: absolute;
  color: #ffd700;
  font-size: 20px;
  font-weight: bold;
}

.possible-move::after {
  content: '';
  width: 20px;
  height: 20px;
  background-color: rgba(76, 175, 80, 0.3);
  border-radius: 50%;
  position: absolute;
}

.game-status {
  font-size: 24px;
  font-weight: bold;
  color: #4CAF50;
}

.current-player {
  font-size: 18px;
  color: #666;
}

.undo-button {
  padding: 10px 20px;
  font-size: 16px;
  background-color: #4CAF50;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;

  &:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
  }

  &:hover:not(:disabled) {
    background-color: #45a049;
  }
}
